Tipranavir, a powerful treatment option for HIV-positive treatment-experienced adults
By Boehringer Ingelheim
Jul 31, 2005, 22:35
Boehringer Ingelheim announced today that the CHMP (Committee for Medicinal Products for Human Use) in London has issued a positive opinion for tipranavir, a non-peptidic protease inhibitor, to treat HIV-infected patients. The new drug will be indicated for highly pre-treated adult patients with virus resistant to multiple protease inhibitors. The positive opinion is seen as a recommendation to the European Commission that authorization to market the drug should be granted in the European Union. Marketing authorization, under exceptional circumstances (comparable to accelerated approval in the US) is expected in the fourth quarter 2005. If approved, tipranavir will be marketed by Boehringer Ingelheim also in Europe under the brand name Aptivus®. Aptivus® was approved for use in the U.S. on 22 June, 2005 and in Mexico on 19 July, 2005 and is currently under review by further regulatory agencies.
New data presented at the 3rd IAS Conference on HIV Pathogenesis and Treatment confirmed that Aptivus® (tipranavir), a novel HIV medication, when boosted with low-dose ritonavir, is a powerful treatment option for HIV-positive treatment-experienced adults. These recent data from the RESIST clinical studies indicate that in highly treatment experienced patients Aptivus provides superior viral load reduction and CD4+ cell count increase compared with a genotypically optimized comparator regimen including lopinavir/r (Kaletra®), ritonavir-boosted amprenavir (Agenerase®) or saquinavir (Invirase®).1
“The increasing prevalence of HIV drug resistance underscores the need for medications like Aptivus that help patients who have become resistant to current treatment options,” said Professor Adriano Lazzarin of the Clinic of Infectious Diseases, San Raffaele-Vita Salute University, Milan, Italy. “These data provide additional evidence that Aptivus is an effective and much needed HIV therapy.”
Aptivus vs. commonly prescribed PIs
The RESIST phase III studies examined the safety and efficacy of ritonavir-boosted Aptivus versus established ritonavir-boosted comparator protease inhibitors (PIs), which included lopinavir/r, amprenavir/r, saquinavir/r or indinavir/r. PIs represent one of the four classes of anti-HIV medications and many are commonly taken with small doses of the PI ritonavir to “boost” their therapeutic levels.
In the RESIST studies conducted in 1483 patients treatment regimen containing Aptivus led to greater 24 week decreases of viral load (amount of virus) in the patients’ blood and greater increases in the amount of immune (CD4+) cells in patients’ systems, than regimen containing lopinavir/r, amprenavir/r or saquinavir/r.2,3 Further sub-analyses found that:
Patients receiving Aptivus/r achieved a more than 2 times greater viral load drop and a more than 5 times greater increase in CD4+ cells compared to patients receiving lopinavir/r.
Patients taking Aptivus/r achieved a 5 times greater viral load drop and a more than 3 times greater increase in CD4+ cells compared to patients taking saquinavir/r.
Patients receiving Aptivus/r achieved a more than 6 times greater viral load drop compared to patients receiving amprenavir/r. Patients taking amprenavir/r did not achieve an increase in CD4+ cells.
*For detailed figures, please see the notes section.
Aptivus with other active anti-HIV medications
Aptivus was more effective in reducing the amount of virus in a patient’s system and suppressing the virus for a longer period of time when it was taken with an additional active anti-HIV drug. In a subset of the RESIST population evaluated at 24 weeks, Aptivus’ efficacy was further enhanced when combined with enfuvirtide, a drug to which only limited resistance can be expected at this time.4 The majority of patients (70%) who had never taken enfuvirtide before and who combined the drug with Aptivus/r, achieved a predefined treatment response, whereas less than one-third (28%) of patients who combined enfuvirtide with lopinavir/r, the market leading PI, achieved this result.
“Boehringer Ingelheim is pleased by these data, which support the use of Aptivus in patients who are in need of new treatment options,” said Dr Andreas Barner, Vice-Chairman of the Board of Managing Directors and Head of Corporate Board Division Pharma Research, Development and Medicine at Boehringer Ingelheim. “Aptivus offers a potent new addition to the HIV treatment armamentarium.”
RESIST Study Design
The RESIST (Randomized Evaluation of Strategic Intervention in Multi-Drug ReSistant Patients with Tipranavir) clinical trial program is one of the largest study programs undertaken with an investigational antiretroviral agent in patients previously treated with multiple combinations of antiretroviral drug regimens.
RESIST-1 and RESIST-2 are randomized, controlled, open-label Phase III trials designed to study the efficacy and safety of Aptivus, boosted with low-dose ritonavir, versus a low-dose ritonavir-boosted comparator PI in patients who have previously taken other anti-HIV medications and who have documented PI resistance. The studies involved 1483 HIV-infected treatment-experienced adults in the US, Canada, Australia, Latin-America and Europe.
Patients enrolled in the RESIST studies were randomly assigned to receive an optimized standard of care regimen containing Aptivus/r 500mg/200mg twice daily or a comparator PI/r at its standard dose. All patients received resistance testing to aid investigators in the selection of the comparator PI and background anti-HIV medications.
Aptivus, a new non-peptidic protease inhibitor, works by inhibiting protease, an enzyme needed to complete the HIV replication process. Based on available clinical and in vitro data, Aptivus is active against most strains of HIV-1 that are resistant to commercially available protease inhibitors. The safety and efficacy of Aptivus in paediatric patients or in adult patients who have not previously taken anti-HIV medications have not been established. Phase 2 and 3 studies in these populations are fully enrolled and ongoing.
In studies to date, Aptivus has been well tolerated by most patients and has a safety profile similar to other PIs. The most commonly reported side effects of at least moderate intensity in patients enrolled in the RESIST studies taking Aptivus/r are gastrointestinal, including diarrhoea, nausea, vomiting and abdominal pain. Fever, fatigue, headache, bronchitis, depression and rash also occurred.
Aptivus boosted with low-dose ritonavir has been associated with reports of liver problems, which have included some fatalities. Extra vigilance is warranted in patients with chronic hepatitis B or hepatitis C co-infection, as these patients have an increased risk of liver toxicity. The most common moderate to severe laboratory abnormalities were elevated liver enzymes and elevated lipid levels. Most laboratory abnormalities were asymptomatic and most patients were successfully treated without discontinuation.
Aptivus does not cure HIV infection/AIDS or prevent the transmission of HIV to others. Patients may continue to develop opportunistic infections and other complications associated with HIV disease.
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